Tensioner lever

Abstract

To provide a simple-structured tensioner lever capable of consistently exerting a correct reaction force to various fluctuations of tension accompanying varying chain behaviors, whereby vibration and noise when the chain runs can be reduced. The tensioner lever of the present invention includes a lever body having a shoe surface that slidably guides a chain; a first pressing spring configured to have a first pressing arm extending from one end of a first helical part, with a distal end portion contacting the lever body to form a first loading point, and a first support arm extending from the other end of the first helical part, with a distal end portion contacting and being supported by a first support part provided to an attachment surface to form a first support point; and a second pressing spring supported on the lever body at a different position from that of the first pressing spring.

What is claimed is: 
     
       1. A tensioner lever comprising: a lever body having a shoe surface that slidably guides a chain and rotatably supported on a pivot shaft standing on an attachment surface; and a pressing mechanism interposed between the lever body and the attachment surface to press the shoe surface toward the chain,
 the pressing mechanism including a first pressing spring and a second pressing spring, 
 the first pressing spring including a first helical part loosely fitted to a cylindrical boss part provided to the lever body, a first pressing arm extending from one end of the first helical part and having a distal end portion contacting the lever body to form a first loading point, and a first support arm extending from the other end of the first helical part and having a distal end portion contacting and being supported by a first support part provided to the attachment surface to form a first support point, 
 the second pressing spring being supported on the lever body at a different position from that of the first pressing spring. 
 
     
     
       2. The tensioner lever according to  claim 1 , wherein at least one of the first pressing spring and the second pressing spring is configured to generate an effective pressing force when the lever body receives more than a predetermined load from the chain and pivots more than a predetermined angle. 
     
     
       3. The tensioner lever according to  claim 1 , wherein the second pressing spring includes a second helical part loosely fitted to a cylindrical boss part provided to the lever body, a second pressing arm extending from one end of the second helical part and having a distal end portion contacting the lever body to form a second loading point, and a second support arm extending from the other end of the second helical part and having a distal end portion contacting and being supported by a second support part provided to the attachment surface to form a second support point. 
     
     
       4. The tensioner lever according to  claim 3 , wherein the first pressing spring and the second pressing spring are set such as to be compressed in opposite directions. 
     
     
       5. The tensioner lever according to  claim 1 , wherein the second pressing spring is disposed such as to generate an effective pressing force when the lever body receives more than a predetermined load from the chain and pivots more than a predetermined angle, and configured to have a larger spring constant than that of the first pressing spring.